Safety mechanism for feed-in wheels of a thread-rolling mechanism



Nov. 10, 1959 A. M. PUTETTI SAFETY MECHANISM FOR FEED-IN WHEELS OF A THREAD-ROLLING MECHANISM 3 Sheets-Sheet 1 Filed June 14, 1955 INVENTOR ATTORNEYS Nov. 10, 1959 A. M. PUTETTI SAFETY MECHANISM FOR FEED-IN WHEELS OF A THREAD-ROLLING MECHANISM 3 Sheets-Sheet 2 Filed June 14, 1955 INVENTOR ATTORNEY5 Nov. 10, 1959 A. M. PUTETTI 2,911,863

SAFETY MECHANISM FOR FEED-IN WHEELS OF A THREAD-ROLLING MECHANISM Filed June 14, 1955 s Sheets-Sheet a ATTORNEYS United States Patent SAFETY MECHANISM FOR FEED-IN WHEELS OF A THREAD-ROLLING lVIECI-IANISM Anthony Michael Putetti, Waterbury, Conn., assignor to The Waterbury Farrel Foundry 8; Machine Company, Waterbury, Conn., a corporation of Connecticut Application June 14, 1955, Serial No. 515,330

4 Claims. (Cl. 80-7) This invention relates to thread-rolling mechanism, and more particularly to a safety mechanism for such a machine whereby the action of the feeding means is stopped if for any reason the feed-in wheel becomes jammed,

In devices for rolling threads upon blanks such as screw or bolt blanks, for example, there are usually provided two cooperating dies, one of which is fixed and the other rotatable, and the blanks are fed by a rotating feed wheel or wheels into the space between the dies. It sometimes occurs that a blank may be oversized, bent or otherwise distorted or in some manner does not conform to standard, and in such case the blank will not enter the space between the dies. This is apt to cause damage to the feeding wheels or possibly even to the dies themselves, and usually when the blank will not enter the die, the operation of the feed wheels meets with abnormal resistance.

- In the present invention a safety drive is provided for the feed-in wheels whereby when the latter meet with unusual resistance, the driving connections give way or become inoperative so that the rotation of the feed wheels may be stopped and, therefore, the latter or any other parts of the machine will not be damaged.

As illustrated in the drawings the feed-in wheels are driven from the shaft which carries the rotatable die so that these elements will be driven in timed relation so that the blanks willenter the space between the dies at the proper time so as to obtain the proper start on the thread. The feed-in wheels are mounted upon a rotatable spindle, and a gear is mounted on the axis of this spindle and driven from a gear upon the shaft of the rotating die. The first-named gear is not, however, secured directly to the spindle but is connected thereto by a releasable clutch mechanism, the parts of which become disengaged when the rotation of the feed wheels meets abnormal resistance.

One object of the present invention is to provide a safety mechanism for the feed-in wheels of a threadrolling mechanism such that the feed-in wheels will be disconnected from their driving mechanism whenabnormal resistance to their rotation is encountered.

A further object of the invention is to provide a threadrolling mechanism wherein cooperating rotatable and stationary dies are provided, and feed-in wheels are arranged to feed blanks into the space between the dies, the feed-in wheels being driven from the shaft of the rotatable die and the driving connections between these parts being so arranged that they will be disengaged when the feed-in wheels meet abnormal resistance to its rotation.

Stillanother object of the invention is to provide a thread-rolling mechanism wherein the rotating-die is provided upon a rotatable shaft and a rotatable feed wheel is driven from this shaft, the driving connections between the shaft and the feed-wheel comprising a gear on the shaft, and a second gear meshing with the first gear, the

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cally disengaged when the feed wheel meets abnormal resistance.

Still another object of the invention is to provide a thread-rolling mechanism of the character described above wherein the feed wheels are mounted upon a spindle driven by a gear coaxially mounted with the spindle and connected thereto by a disengageable clutch mechanism, and the gear being arranged for adustment about the axis of the spindle so as to vary the position of the gear with respect to the feed wheels. 1

To these and other ends the invention consists in the novel features and combinations of parts to be hereinafter described and claimed.

In the accompanying drawings:

Fig. 1 is a top plan view of a thread-rolling mechanism embodying my invention;

Fig. 2 is a sectional view on line 2-2 of Fig. l;

Fig. 3 is a top plan view of the releasable clutch mechanism;

Fig. 4 is a similar view showing the parts in another position;

Fig. 5 is a side elevational view of the mechanism shown in Fig. 3; and

Fig. 6 is a side elevational view of the mechanis shown in Fig. 4.

To illustrate a preferred embodiment of my invention I have shown a thread-rolling mechanism comprising a frame 10 in which is rotatably mounted a shaft 11 to which is secured a rotatable die 12. The shaft 11 is provided with a reduced upper end portion 13 within a bearing collar 14.

Secured upon the upper end 13 of the shaft 11 isla gear designated generally by the numeral 15, this gear comprising two halves 16 and 16 so that the teeth of one portion of the gear may be adjusted with respect to the teeth of the other in order to provide a snug engagement and prevent backlash between the teeth of this gear and the teeth of a mating gear which drives the feed-in wheels, as will be hereinafter described. The use of a split gear of this kind where one portion may be adjusted relatively to the other maintains a smooth running relationship between the rotatable die and the feed-in wheels. This gear may be held in place upon the shaft by the nut 17..

A cooperating die 18 is secured upon the frame, this being the stationary die. This die is held by a die block engageable clutch mechanism adapted to be automati- 19 which may be adusted toward and from the rotating die 12 by means of adjusting screws 20 and 21 in a portion of the frame. As will be noted from Fig. l, a space is left between the rotating and fixed dies so that. the shank of a blank may be introduced between the dies and a thread rolled thereon.

As shown more especially in Fig. 2, a feed-in mechanism is provided which consists of a pair of disk-like wheels 23 and 24. These wheels are provided with notches 25 in which the blank is received so that it may be picked up from the feed chute 26 (Fig. 1) and carried into the space between the dies. These feed wheels are secured upon the lower end of a shaft or spindle 27 and may be secured thereto in any desired manner. As shown, they are clamped between a shoulder 28 on the spindle and spacing sleeves 29, 30 and 31 by the nut 32 threaded upon the lower end of the spindle.

The spindle 27 is rotatably mounted in a sleeve 33, this sleeve in turn being rotatably mounted in a bracket 34 adjustably or oscillatably mounted -;upon abearing collar 35 which is coaxial with the shaft 11 so that this bracket 34 which carries the spindle 27 and sleeve 33 may be adjusted about the axis of the shaft 11. The bracket is provided with arms 36 (Fig. 1) having elongated slots 37 therein through which' 'm'ay be passed a bolt 38 secured to the frame so that the bracket 34 may be locked in adjusted position by nuts 39 threaded upon the bolts 38. The bracket may be spaced from the frame by spaced sleeves 40 surrounding these bolts. It will be seen that adjustment of the bracket around the axis of the shaft 11 permits the feed-in wheels to be swung away from the stationary die for replacement and also provides adjustment for feed-in Wheels of different d1- ameters so that they may be disposed .in proper relation .to the chute 26 and to the mouth of the opening between the dies.

Secured to the sleeve 33 is a gear hub 41 to which is adjustably secured a gear 42, the teeth of which mesh .with those of the split gear 15. As shown more especially in Figs. 1, 2 and 3, this gear is adustably mounted upon the hub by means of arcuate slots .43 provided in the gear and bolts 44 passing through the gear and threaded into the hub 41. Thus the gear may be adjusted relatively to the hub about the axis of the spindle 27 so as to adjust this gear relatively to :the feed-in wheels and position the work slots in the feed-in .wheels in proper relation to the dies.

Asillustrated, the gear hub 41 is frictionally connected to the sleeve 33, the gear hub being clamped between a friction plate 46 and a shoulder 47 on the sleeve, friction collars 48 being provided upon each side of the hub. The friction plate 46 is held in placeby the nut 50 threaded upon the sleeve. If desired, the hub could befixed rigidly to :the sleeve or formed integrally therewith.

As previously stated, a 'disengageable clutch mecha nism is provided between the feed-in wheels and the driving mechanism therefor. In the embodiment shown, this mechanism is positioned between the sleeve 33 and the spindle 27.

Secured to the sleeve 33 by a flattened pin ,52 is a plate 53, and a cooperating plate 54 is secured to the spindle by the flattened pin 55. The plate 53 is pro- .vided with a radially disposed V-shaped groove or notch :56 in its ,upper surface and a pin 57 is slidably mounted in an opening in the plate 5.4, the lower end of this pin being pointed as shown at 58 and adapted to rest in the groove 56 when the clutch plates 53 and 54 are engaged. It will be apparent, however, that as the groove 56 is of V-shaped form, the pin 57 would tend to ride out of the groove 56 upon a torque applied to the sleeve or spindle ifmeans were not provided to hold the pin in place. As will be described below, I provide springpressed means for releasably holding the pin in place so that the pin may be disengaged from the groove when the feed-in wheels encounter abnormal resistance to their rotation, as will be the case if it is attempted to deliver anonstandard blank to the dies.

.Referring particularly to Figs. 3 and 4, it will be noted that the head of the pin 57 is beveled on both upper and lower sides, as shown at 60 and 61. A retainingplate .62 isrotatably mounted on the upper end of the spindle 27, this plate being provided with wing portions 63, each having a forward edge beveled on its upper and lower surfaces, as shown at 64 and 65. A torsion spring 66 engagesatone end a pin 67 secured to the retaining plate 62 and at the other end a .pin 68 secured to the upper clutch plate 54. This spring tends to rotate the plate 6.2 in a clockwise direction, as viewed in Fig. 3, so as to normally maintain the beveled edge 64 over the beveled portion 60 of the head of the pin 57 and normally hold the pin in the groove 56, as shown in Fig. 5.

When, however, the spindle 27 meets with abnormal resistance to its rotation, the pin 57 will be cammed upwardly out of the V-shaped groove 56 due to the shape of theend of the pin and the walls of the groove and will ride upon the upper surface of the plate 53, as shown in Fig. 6. At this time the upper beveled edge 65 of the retaining plate 62 will'engage the lower beveled edge 61,0f the head of the pin 57 and hold the pinin its upward position so that the clutch plates are disengaged, as shown in Fig. ;6.

When the parts are in this position it will be apparent that the sleeve 33 may continue to rotate without effecting rotation of the feed-in wheels. When the defective blank has been removed from the dies and the machine is again ready for operation, the retaining plate 62 may be moved from the position shown in Fig. 6 so as to disengage the surface 61 of the head of the pin and permit the latter to drop into the groove 56. The plate 54 may-be turned to the proper position to permit this reengagement of the pin in the groove.

It may also be noted that should the safety clutch ust described fail to operate for any reason, the gear hub 41 can turn between the friction collars 48, but this arrangement is merely a precautionary measure to prevent great damage to the machine if for any reason the safety clutch mechanism fails to operate.

While I have shown and described a preferred embodiment of my invention, it will be understood that it is not to be limited to all of the details shown, but is capable of modification and variation within the spirit of the invention and within the scope of the claims.

What I claim is:

1. A machine for rolling threads on screw blanks or the like comprising a frame, a rotatably mounted dn'ven shaft carried by the frame, cooperating spaced stationary and rotatable dies, the latter of which is carried by said shaft, a feed wheel adapted to feed blanks to the space between said dies, 21 second rotatable shaft upon which said feed wheel is mounted, means for rotating said first shaft, means for rotating said feed wheel shaft comprising a sleeve rotatably carried by the frame and embracing the feed wheel shaft, a plate secured to said sleeve, a cooperating plate secured to the feed wheel shaft, means connecting said plates comprising a pin slidably mounted in one thereof and a cooperating groove in the other thereof to receive said pin, said pin having a beveled head projectingabove the plate in which the pin is mounted, a retaining member rotatably mounted on said plate, said retaining member having a cam portion adjacent the head of the pin, and a torsion spring urging said retaining member in a direction to engage the cam portion with the head of the pin to releasably hold the latter in said groove.

2. A machine for rolling threads on screw blanks or the like comprising a frame, a rotatably mounted driven shaft carried by the frame, cooperating spaced stationary and rotatable dies, the latter of which is carried by said shaft, a feed wheel adapted to feed blanks to the space betweensaid dies, a rotatable shaft upon which said feed wheel is mounted, means for rotating said shafts, the means for rotating said .feed wheel shaft comprising a sleeve rotatably carried by the frame and embracing the feed wheel shaft, a plate secured to said sleeve, a cooperating plate secured to the feed wheel shaft, means connecting said plates comprising a pin slidably mounted in one thereof and a cooperating groove in the other thereof to receive said pin, spring pressed means normally holding said pin in said groove, means to drive said sleeve, a bracket in which said sleeve is mounted, and means mounting said bracket on the frame for adjustment about the axis of the rotatable die.

3. A machine for rolling threads on screw blanks as set forth in clairn l wherein the head of the pin is beveled upon both upper and lower surfaces, and the cam portion on the retaining member is adapted to engage either of saidsurfaces selectively to releasably hold the pin in or out of said groove.

4. A machine for rolling threads on screw blanks or the like comprising a rotatably mounted driven shaft, cooperating spaced stationary and rotatable dies, the latter of which is carried by said'shaft, a feed wheel adapted to feed blanks to the space between said dies, a second rotatable shaft parallel to the first shaft upon whichsaid .feed wheel is mounted, means for rotating said last-named shaft from the shaft of said rotatable die to rotate the feed wheel in timed relation to the rotation of the die comprising meshing gears, one mounted on each shaft, a gear hub drivingly. connected with the feed wheel shaft and mounted coaxially therewith, said gear on the feed wheel shaft being connected toisaid hub for angular adjustment of the feed wheel shaft with respect to the gear about the axis of the latter to adjust the feed wheel relatively to the rotatable die, and means for adjusting the feed wheel shaft in an arcuate path about the axis of the rotatable die.

References Cited in the file of this patent UNITED STATES PATENTS 251,874 Harvey Jan. 3, 1882 6 Gass et a1 Apr. 3, 1883 Hubbell Apr. 4, 1899 Painter et al Feb. 20, 1900 Huneke July 25, 1911 White Dec. 17, 1929 McLaughlin Oct. 25, 1938 Stahmer Sept. 8, 1953 Fray Aug. 10, 1954 Blakeslee June 3, 1958 A line 6, in the list of referencee UNITED sTATEs PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 2,911,863 November 18, 1959 Anthony Michael Putetti It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2', line 8, for ",adustm-ent" read. em adjustment F line 4'7, for "adusted" read me adjusted column 3, line l4, for "aduetably" reed adjuetably column ,4, line 12, for "net" read me just *5 column 6,,

cited 2 under UNITED STATES PAJIENIS, for

the patent number "1,134,526" read 23,134,526

Signed and sealed this 26th day of April 1960.,

(SEAL) Attest:

KAEL n, TAXLINE Attesting Oflicer ROBERT (J. WATSON Commissioner of Patents 

